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Protecting Your Family from Lead in the Home
Jason P. de Koff, Brad D. Lee, and A. Paul Schwab
Purdue University Department of Agronomy
Lead is a versatile metal that has been widely used for
5,000 years. But overexposure to lead can lead to serious
health consequences, especially in children. One study
shows that the concentration of lead in the bodies of
humans today is four to 10 times greater than lead levels in
early man (Patterson et al., 1991).
This publication identifies sources of lead that are common
in the home, describes the risks associated with lead
exposure, and recommends ways to remove or reduce lead
exposure.
After initial absorption, lead remains in the bloodstream
for a few weeks and is eventually deposited in the bone
structure where it can remain for a lifetime (U.S. EPA,
1998). Table 1 shows specific effects of lead exposure.
Changes in Lead Use
The last three decades have brought significant changes
in lead use in the environment (Figure 1). Lead has been
Versatile, But Potentially Harmful
Lead has been a very commonly used metal because it
resists corrosion and is one of the easiest metals to mold
and shape. It has been used in everything from paints and
gasoline to batteries, pipes, and canned goods.
But this versatility has included some unnecessary risks.
Lead can adversely affect the structure and function of
various organs and tissues in children and adults. Children
ages 6 and under are more sensitive to lead exposure
because of their smaller size, greater rates of absorption of
lead in the digestive tract (Casas and Sordo, 2006), and their
ongoing physical and neurological development (Lanphear
et al, 1998). According to the Indiana Department of Health
55,260 children 7 and younger were tested for lead in 2006.
Of those, 520 had lead poisoning or elevated levels of lead.
The human body cannot effectively distinguish between
lead and calcium, which leads to harmful effects when the
body uses lead in place of calcium (Casas and Sordo, 2006).
Figure 1. Changes in Lead Use
These charts show the primary commercial uses of lead in 1978
(when lead was removed from gasoline and paint) and 1998
(adapted from Smith, 2004).
Table 1. Effects of Lead Exposure
Lead Exposure Level
Effects
Low
Few detectable symptoms. Blood tests are the best way to determine exposure.
Medium
headaches, insomnia, abdominal pain, constipation, reduced sperm count, increased risk of miscarriage
High
deafness, blindness, paralysis, kidney failure
Additional risks for children
lower IQ, learning disabilities, attention deficit disorders, violent behavior
Adapted from U.S. EPA, 1998; Casas and Sordo, 2006.
Purdue Agronomy
Crop, Soil, and Environmental Sciences
Sources of Exposure
Lead in Soil
According to the U.S. Department of Health and Human
Services’ Agency for Toxic Substances and Disease
Registry, ingesting and inhaling soil or dust is the main
source of lead exposure in the home environment.
Lead in soil can come from natural sources, including
rocks and minerals, vegetation, and volcanic activity. This
naturally-occurring lead contributes about 24,500 tons of
lead to the atmosphere each year, but makes up a very small
percentage of the total 20 million tons of lead that was
measured in the atmosphere 30 years ago when lead was
still used in gasoline (Nriagu, 1988).
Once lead was eliminated from gasoline production
beginning in 1978, most of the remaining airborne lead fell
to the earth either as dust particles or with precipitation.
Due to its chemistry, lead in the soil is held tightly by clay
and organic matter in the upper 6 inches of soil (Castellino
et al., 1995). This tight binding means it can take a very
long time — 90-200 years — for just 10 percent of the
lead content to be removed by drainage (Tyler, 1981). In
Indiana, the average upper layer of soil contains high clay
and organic matter levels, allowing high levels of lead to
bind to and remain in the surface soil.
The Indiana Department of Environmental Management
(IDEM) and U.S. Environmental Protection Agency (EPA)
have set standards for lead levels in the soil. In areas where
children may come in contact with the soil, the maximum
lead level is 400 parts per million (ppm), or about 13 ounces
of lead per ton of soil. Uncontaminated soils commonly
contain natural lead levels of 10 to 70 ppm (Shacklette and
Boerngen, 1984). Contaminated soils in urban areas and
near roads have been found with levels as high as 10,900
ppm due to the past use of lead in gasoline. A study of soils
in urban Indianapolis observed that these high lead levels
were as far as 140 feet from roadways (Figure 2).
Tainted soil is a major source of lead exposure for young
children because they tend to put objects, including their
unwashed hands, in their mouths. The EPA estimates that
the average child can ingest up to 200 milligrams of soil per day this way. Over time, consuming this much soil
could lead to a range of problems if lead concentrations are high enough.
Distance from Roadway (feet)
Figure 2. Lead Levels and Distance from Road
This chart shows the level of lead in soils when tested at various
distances from Washington Street in Indianapolis (adapted from
Filippelli et al., 2005).
Food crops grown in lead-contaminated soils seldom
contain elevated lead content and are relatively safe for
human consumption. The amount of lead available to plants
in the soil (the amount not bound in soil clays and organic
matter) is usually very small and is mostly bound up in
the roots. Only about 3 percent of the lead a plant takes in
makes its way to the aboveground vegetation (Zimdahl,
1975). For example, one study showed that a tomato plant
transferred around 4 percent of the total lead transported to
the consumable fruit (Figure 3).
715 ppm
Lead Content (ppm)
banned from use in many applications and government
agencies routinely monitor lead levels in drinking water
and the atmosphere. However, lead remains important,
especially in making automotive batteries where up to 86
percent of old batteries are recycled to make new ones
(Smith, 2004). This recycling helps reduce current lead
pollution while still enabling its use.
Soil Lead Concentration (ppm)
Protecting Your Family from Lead in the Home—HENV-101-W
22 ppm
<10 ppm
Distance from Roadway (feet)
Figure 3. Lead Content of Plants Grown in Contaminated Soil
This graph shows the lead contents of different parts of a tomato plant
grown in lead-contaminated soil (3,470 ppm). The parts were rinsed
with water to remove soil and dust before analysis (adapted from
Finster et al., 2004).
However, root crops (such as carrots and potatoes) and
leafy vegetables (such as lettuce and spinach) should not be
grown on lead-contaminated soil because these plants tend
to accumulate lead more than others.
The main lead exposure risk from food crops is not from
the inside, but from the outside of the food. Dust from
Protecting Your Family from Lead in the Home—HENV-101-W
contaminated soil that accumulates on the exterior of
fruits and vegetables (either from the soil beneath or the
atmosphere) usually will contain more lead than the plant
itself (Castellino et al., 1995). So, it is a good idea to wash
all garden produce before use, even if it is organically
grown without chemical pesticides or fertilizers.
Lead in Drinking Water
Lead-contaminated water is of particular concern because
the body more readily absorbs lead from water than from
other sources (Casas and Sordo, 2006). Natural lead levels
in water are usually less than 25 parts per billion (ppb),
which is equivalent to 2 ounces of lead in an Olympic-size
swimming pool. Municipal water treatment plants usually
remove most lead from the water because the EPA requires
lead levels to be 15 ppb or less.
If a household’s water supply is contaminated with lead, the
contamination usually comes from the piping that transports
water from the supply line throughout the house. If the
pipes are made from lead, if they are held together with
lead solder, or if there are brass fixtures, then the lead they
contain can be leached into the water (U.S. EPA, 1998).
Changes to the Safe Drinking Water Act in 1988 restricted
the use of lead piping and components in residential homes,
but those living in homes built before then may be at risk of
exposure to high lead levels in their water.
Lead in Paint
Lead-based paints also are a significant source of lead
exposure that can be found both on the interior and exterior
of the home. Lead was used as a pigment and drying agent
in paint until it was banned from residential use in 1978.
According to the U.S. Centers for Disease Control and
Prevention, 83 to 86 percent of homes built in the United
States before 1978 contain lead-based paint which may
contain 20 to 30 percent lead (Casas and Sordo, 2006).
Children are frequently drawn to lead paint chips because
of their sweet taste, and exposure to lead paint accounts for
as much as 90 percent of childhood lead poisoning (Casas
and Sordo, 2006). IDEM recommends testing all children
for lead exposure who live or play on property built before
1978.
Preventing Lead Exposure
The EPA has made a number of recommendations for
reducing lead exposure in the home:
• Keep your home clean
Make sure that most surfaces are regularly dusted,
washed, or vacuumed, especially if children are present.
HEPA-filters, found in many vacuum cleaners, are
equipped to trap lead particles.
• Run cold tap water 15-30 seconds before use
Water resting in lead pipes may slowly accumulate lead.
This will flush the water that has been sitting in the pipes.
Using cold instead of hot water can reduce the amount of
lead that may dissolve. Carbon, sand, and cartridge filters
do not remove lead from water.
• Eat a well-balanced diet
Studies show that vitamins and minerals can either reduce
the body’s lead absorption or increase its release and
excretion from the body. Diets high in fat can enhance
lead absorption.
• Test for lead
Hire a certified risk assessor or lead inspector who can
test for lead in both your home and soil. A risk assessor
can also make specific recommendations for reducing
your risk of lead exposure. For information on testing
your water, call the Safe Drinking Water Hotline listed
below.
• Reduce bare soil
Grow grass in bare patches to cover the soil and reduce
the amount of dust that can accumulate and be ingested.
• Remove sources of lead
Replace lead pipes or components and remove chipped
or peeling lead-based paint carefully. Always wear a dust
mask or respirator to minimize exposure.
• Get a blood test
If you believe you or your family is at risk for lead
exposure, get a blood test and consult your doctor about
possible treatments
Find Out More
Contact the following agencies for more information about
lead in the home environment.
In Indiana
Indiana Department of Environmental Management
(888) 574-8150
www.in.gov/idem/your_environment/lead
Indiana Department of Health
(317) 233-1325
In the United States
Environmental Protection Agency
(800) 424-LEAD (5323)
Safe Drinking Water Hotline
(800) 426-4791
Protecting Your Family from Lead in the Home—HENV-101-W9
Other Home & Environment Publications
Visit the Home & Environment Web site for science-based
information about homes and the home environment: www.
ces.purdue.edu/HENV/index.htm.
References
Agency for Toxic Substances and Disease Registry. 2005.
Lead. CAS #7439-92-1. Agency for toxic substances and
disease registry, Health and human services department,
Atlanta.
Casas, J.S., and J. Sordo (eds.) 2006. Lead: chemistry,
analytical aspects, environmental impact and health
effects. Elsevier, The Netherlands.
Castellino, N., P. Castellino, and N. Sannolo (eds.) 1995.
Inorganic lead exposure: metabolism and intoxication.
CRC Press, Inc. Boca Raton, FL.
Filippelli, G.M., M.A.S. Laidlaw, J.C. Latimer, and R.
Raftis. 2005. Urban lead poisoning and medical geology:
an unfinished story. GSA Today 15(1):4-11.
Finster, M.E., K.A. Gray, and H.J. Binns. 2004. Lead levels
of edibles grown in contaminated residential soils: a field
survey. Sci. Total Environ. 320(2-3):245-257.
Lanphear, B.P., T.D. Matte, J. Rogers, R.P. Clickner, B.
Dietz, R.L. Bornschein, P. Succop, K.R. Mahaffey,
S. Dixon, W. Galke, M. Rabinowitz, M. Farfel, C.
Rohde, J. Schwartz, P. Ashley, and D.E. Jacobs. 1998.
The contribution of lead-contaminated house dust and
residential soil to children’s blood lead levels. Environ.
Res. 79:51-68.
Nriagu, J.O. 1988. Global inventory of natural and
anthropogenic emissions of trace metals to the
atmosphere. Nature 279:409-411.
Patterson, C., J. Ericson, M. Manea-Krchten, and H.
Shirahata. 1991. Natural skeletal levels of lead in Homo
sapiens uncontaminated by technological lead. Sci. Total
Environ. 107:205-236.
Shacklette, H.T., and J.G. Boerngen. 1984. Element
concentrations in soils and other surficial materials of
the conterminous United States. U.S. Geological Survey
Professional paper 1270. U.S. Gov. Printing Office,
Washington, D.C.
Smith, G.R. 2004. Lead recycling in the United States
in 1998. p. F1-F9. In S.F. Sibley (ed.) Flow studies for
recycling metal commodities in the United States. U.S.
Geological Survey, Circular 1196-A-M.
Tyler, G. 1981. Leaching of metals from the A-horizon of a
spruce forest soil. Water Air Soil Pollut. 15:353-369.
U.S. EPA. 1997. Exposure factors handbook. National
Center for Environmental Assessment, U.S. EPA Office
of Research and Development, Washington, D.C.
U.S. EPA. 1998. Lead in your home: a parent’s reference
guide. EPA 747-B-98-002.
Zimdahl, R.L. 1975. Entry and movement in vegetation
of lead derived from air and soil sources. 68th Annual
meeting of the Air Pollution Control Association, Boston, MA.
Authors:
Jason P. de Koff, Graduate Research Assistant,
Department of Agronomy, Purdue University
Brad Lee, Assistant Professor and Soil and Land Use
Extension Specialist, Department of Agronomy,
Purdue University
A. Paul Schwab, Professor of Soil Environmental
Chemistry, Department of Agronomy, Purdue
University
Visit the Home & Environment Web site for science-based
information about homes and the home environment: http://www.ces.purdue.edu/HENV/index.htm.
9/07
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